The present invention relates to a memory card system and an access method for memory cards. More particularly, it relates to a system having a memory card which is rendered versatile as a data filing medium.
Magnetic discs represented by floppy discs have generally been employed as data file media in data processing systems. Recently, a memory card having a built-in IC memory chip has been developed and has come into use also as a data file medium. In a case of utilizing the memory card as the data file medium, the recording format thereof can be determined independently of that of the floppy disc. Since, however, the floppy disc has long been used as the data file medium and software premised on the floppy disc has been accumulated, the recording formats of the memory cards should be arranged such that they can accept the recording format of the floppy disks, in order to render the memory card a versatile data file medium. The recording format of the floppy disc is configured of an index area and a data area. The index area holds file names serving as the indexes of the data area, the addresses of the data area, etc.
The official gazette of Japanese Patent Application Laid-open No. 138483/1988 discloses an IC card device, the memory of which is composed of a management area and a data area. The management area bears management data which includes the label names, addresses and data lengths of the data area.
The official gazette of Japanese Patent Application Laid-open No. 184889/1988 discloses an IC card having a built-in IC chip, the memory of which is composed of a plurality of areas [00-FF. The area [00] bears information which defines the start addresses, area sizes and data output methods of the areas [01-FF].
The recording formats of both the patent applications laid open are similar to that of the floppy disc.
To allow data to be accessed, the floppy disc has its data positions designated by track addresses and sector addresses. In addition, there are several kinds of floppy discs in which the numbers of bytes to be recorded per sector vary, i.e. 128, 256, 1024, etc. Data is not transferrable between media having unequal numbers of bytes to be recorded per sector. The concepts of tracks and sectors are not included in the above discussed memory cards, and the data transfer between the memory cards is possible. However, in the case of utilizing the memory cards as the data file media to replace the floppy discs, memory cards need to be compatible with the floppy discs and to transfer data from and to the floppy discs.
An object of the present invention is to provide a memory card the data of which is compatible with the filed data of a floppy disc.
Another object of the present invention is to provide a memory card system and a method which serve to access such a memory card.